If sampling conventionally (not grid sampling) for soybean cyst nematodes, collect 15-20 soil cores in a zigzag pattern from no more than 20 acres. The 20-acre parcels of the field do not need to be square or rectangular; samples can be collected from zones according to the agronomic features of the field.

If grid sampling for soybean cyst nematode: collect one or two extra soil cores from every grid cell sample and combine these extra cores from the number of cells that represent approximately 20 acres.